Journal of the Indian Society of Soil Science

Field experiments were conducted during kharif 2009 and 2010 with rice as the test crop using different vermicomposts prepared from different organic residues under integrated nutrient management at Regional Agricultural Research Station, Anakapalle, Andhra Pradesh. The present work was undertaken to study the changes in different enzyme activities during vermicomposting of varied organic residues and impact of different vermicomposts under integrated nutrient management with special reference to soil enzymes as soil health indicators under submerged rice soil. Among different vermicomposts, vegetable market waste and weed composts exhibited highest urease and dehydrogenase activity and the cellulase activity was more in cane trash and rice straw composts. Urease and dehydrogenase activity at flowering stage was increased by 136 and 63.2 per cent, respectively in the plots treated with 75% chemical fertilizers with vegetable market waste vermicompost @ 2.5 t ha⁻¹ over 100% recommended dose of fertilizer nitrogen (RDFN). Significantly higher acid phosphatase activity of 42, 92, 164 and 73 μg PNP released g⁻¹ soil h⁻¹ at initial, tillering, flowering and at harvest of second year crop was recorded in the treatment with 75% RDFN with vegetable market waste vermicompost @ 2.5 t ha⁻¹ and it was on par with 75% RDFN+weed vermicompost @ 2.5 t ha⁻¹. Enzyme activities increased with the age of the crop and attained maximum activity at flowering and thereafter the activity decreased gradually at maturity. Conjunctive application of organics along with inorganics exhibited higher grain yields (5.85 t ha⁻¹) over application of inorganics only (4.70 t ha⁻¹).